So for the curious the parts I used for the power supply are as follows:

1. Custom PCB which I had made in 4 oz copper from Epec Tech. BTW I've got a large back stock of these if others are interested.

2. Toroid is a Toroid Tech custom 500VA with 138VAC primary and 56VAC Secondary's which work out to around 49VAC at 120VAC in. So after rectification it works out to about 67V rails.

3. Caps are Panasonic 6800uF T-HA types. Snubbers are WIMA .1uF pulse caps. The square looking caps on the end there are Mundorf RXF in Oil 5.6uF.

4. Inductors are 14AWG copper foil 2.2mH Erse.

5. Dual Bridge rectification is handled by two IXYS FBS 10-06 SC.

6. Wiring is a mix of Cardas chassis wire, Vampire Copper cast and just plane old stuff from home depot for grounding.

7. RCA jack is Vampire as well as the binding posts. The pure copper types.

This is my first project so I'm sure there may be a lot to criticize here so please be kind folks as I'm a noob. I have learned quite a bit but I realize how much more knowledge is required to be really effective at this hobby.

Alright so I mentioned that I've got 5 of these amps and only two are working currently. Another two are on hold cause one amp module has a defective part some place and doesn't measure right or pass the build checks that Ledeaudio provides for having a working amp.

However that leaves just one that was working until last night. All of a sudden the gain dropped to almost nothing and the sound is super scratchy and messed up. I have a feeling that one of my L-MOS devices died. These are the 2JS162 and 2KS1058 types.

If anyone can provide feedback on what a good strategy would be to track down and replace a defective MOSFET that would be most helpful. Would it be as simple as taking a working unit and compare voltages on each leg of each device?

Many of you may want a schematic and unfortunately I don't believe I can post one here as the amp design is copy write to Zus audio unless Russ says its alright. But is someone is willing to help me out I believe I can share the info directly via PM.

Just sat down for a bit to really listen to the amps and I am indeed very impressed certainly the best pair of amps I've ever owned and some of the finest I've heard the Slone Totem-Pole amps are forreelz folks.

I have seen the Opti-MOS schematic available on the web but not the Totem-Pole. If Rus says its alright I will post up the Totem-Pole schematic. But yes I believe that both the opti and totem-pole are copyright to Zus Audio. Just don't want to step on any toes.

If anyone can provide feedback on what a good strategy would be to track down and replace a defective MOSFET that would be most helpful. Would it be as simple as taking a working unit and compare voltages on each leg of each device?

TJ[/QUOTE]

Checking the voltage drop across all output resistors (as in quiescent current setting ) and comparing with the good one would be a good place to start . Plus comparing the DC offset voltage .